Although the traditional spring mattress is the dominant category of mattresses sold within the United States, both latex foam mattresses and visco-elastic (memory) foam mattresses have been sold in the U.S. as specialty-category mattresses.
Both latex and memory foams have benefits and drawbacks in mattress construction and design. Latex foam has a very quick recovery rate (i.e., is “bouncy”), is highly breathable and can be produced using natural or synthetic materials. If natural materials are used, the mattress can be marketed as such, adding to its desirability in the marketplace. Nonetheless, latex foam mattresses have the highest average return rate of any type of mattress sold in the U.S.—usually due to the resonant “bouncing” that the user feels on a latex foam mattress and/or inadequate pressure relief.
The market for memory foam mattresses was built nearly single-handedly by Tempur-Pedic through novel marketing techniques, such as an association with space-age technology and the image of a handprint “stuck” in the foam top layer after the hand is removed. Due to its slow recovery (or memory), visco-elastic memory foam was marketed as an aid for pressure relief and to enable isolation of one sleeper from another because the foam does not translate vibration. But memory foam mattresses also have a somewhat high return rate, often due to complaints such as: 1) “getting stuck” (i.e., not being able to turn over when changing sleeping positions); 2) overheating (the foam is not highly breathable and the contouring causes the foam to closely hug large portions of the body limiting air flow); and 3) not being conducive for comfort during sex because of the tendency to “get stuck.”
Further, both latex and memory foam are expensive materials. Manufacturers often use them only for the top layer(s) of a mattress, often referred to as the comfort layer(s). The comfort layer(s) are usually 1-5″ thick and typically consist of 1-3 different foam types laminated together. Beneath these layer(s), regular polyurethane foam is typically used to provide some support and to increase mattress thickness. Some newer “hybrid” mattresses use pocketed spring coils instead of polyurethane foam. To combat the “stuck” feeling of memory foam, some manufacturers have developed quick-response memory foam. Other manufacturers use thinner layers of memory foam (atop poly foam) to limit the depth that user can sink into the foam. A few manufacturers have put latex foam underneath the memory foam to benefit from the quick return (i.e. bounce) that the latex foam provides. But this solution may not solve the problems noted above where memory foam is the top layer of the mattress.
Accordingly, there is a need for a novel foam mattress construction that couples the contouring pressure relief of memory foam with quick-recovery of latex foam that prevents users from getting “stuck” in the memory foam and improves the springiness of the mattress. Such an arrangement will benefit from the breathability and bounciness of latex foam while mitigating the resonant bouncing and poorer pressure relief characteristics of latex foam.
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The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.